Stand on the right, Walk on the left.
It is a manner of using the BTS and MRT escalators.
The advantage of organizing the courtesy like this is that it seems likely to stop from booking people who them are in a rush puth. Because It the line is disorganized and some one is rushing over to work, or if there's metter of urgency going on , they might casually need to bump into us and cause to lose over balance, and can lead to an accident . So we all have to follow the rules of using the escalators set by society in order to avoid frequent accident.